Simulation of Microwave Thawing

In this study, one dimensional model food thawing (from -20 oC until surface temperature reached 70 oC) by microwave was simulated by implicit finite different method and SCILAB. Powers of microwave were 300, 600, 800, 1000, 1200 and 1500 Watt, and sizes (half thickness) of model food were 0.5, 1, 2 and 4 times of water penetration depth (1.68 cm). On-Off cycles of 100-0,70-30,50-50,30-70 percent of power with fixed interval time was also investigated. The result showed that, for sample size around 1 times of penetration depth, the higher power supply, the lower temperature difference was founded. As size increasing leaded to rapidly rise of surface temperature and slowly melted at center of food. For on-off cycle, using 50-50 percent of power might be suitable for low temperature difference with appropriate melting time. Finally, on-off operation should be started after surface melting and was not significantly affected on large sample sizes.